Twist drill bit Irwin 10502564 — 9.5 mm diameter, single piece

The Irwin twist drill bit model 10502564 is a single-piece HSS cobalt drill designed for demanding metalworking tasks. With a 9.5 mm diameter and a 125 mm overall length, this monopiece bit is manufactured to DIN 338 standards and features 5% cobalt alloy for improved heat and abrasion resistance. The 135° split point reduces walking and enables immediate penetration, making it suitable for through-holes, pilot holes and maintenance drilling in a workshop or on-site environment.

Advantages

The cobalt-enhanced high-speed steel composition increases durability and cutting life when drilling tougher and heat-resistant metals. Heavy-duty web construction provides structural strength and resistance to breakage under load. The 135° split point geometry delivers precise centring and faster entry without the need for centre punching in many applications. Cylindrical shank ensures compatibility with standard drill chucks and stable clamping.

Suitable for

• Drilling holes in alloyed and heat-treated steels
• Piercing stainless steel and other corrosion-resistant metals
• Workshop maintenance, machinery repair and metal fabrication
• Construction tasks that require precise metal drilling

Key specifications

• Type: twist drill bit (single piece)
• Diameter: 9.5 mm
• Total length: 125 mm
• Material: high-speed steel with 5% cobalt
• Point angle: 135° split point
• Shank: cylindrical
• Standards: manufactured to DIN 338
• Suitable materials: alloyed steel, metal, stainless steel

How to use

Select an appropriate drill chuck and secure the 9.5 mm cylindrical shank firmly. Use steady feed pressure and correct spindle speed according to the workpiece material—lower speeds for hardened or stainless steels—to reduce heat buildup. Apply cutting fluid or lubricant when drilling alloyed or hardened metals to extend tool life and improve chip evacuation. For best accuracy, clamp the workpiece securely and, where necessary, create a small centre dimple or use the split point to start drilling precisely.

Usage recommendations

Use reduced spindle speed and continuous cutting fluid when drilling hardened or stainless steels; avoid excessive side load or twisting to prevent premature wear or breakage. Periodically clear chips from the flutes and inspect the cutting edges for wear. Replace the bit when chipping or dulling affects performance to maintain hole quality and safety.